Low reflection optical fiber termination device and method using same

Abstract

A low reflection termination device comprised of a tubular glass housing having an interior cavity, an optical fiber having an end with a portion of the end being formed by the application of heat into a glass bead and extends into the glass housing with the glass bead positioned within the interior cavity, a clear cured epoxy disposed within the cavity of the housing surrounding the glass bead, and a light absorbing material which coats the tubular glass housing.

Having described the invention, the following is claimed: 
     
       1. A method for terminating an end of an optical fiber, comprising the steps of: heating an end of an optical fiber until said end softens and forms a bead of glass thereon;   inserting said end of said fiber into a tube filled with a curable epoxy; and   curing said epoxy to fix said end within said tube.   
     
     
       2. A method as defined in claim 1, wherein said epoxy is a clear UV curable epoxy. 
     
     
       3. A method as defined in claim 2, wherein said UV curing epoxy has an index of refraction approximately equal to the index of refraction of said bead of glass. 
     
     
       4. A method as defined in claim 3, wherein said tube is glass and has an index of refraction approximately equal to the index of refraction of said bead of glass. 
     
     
       5. A method as defined in claim 4, further comprising the step of coating said tube with a light absorbing material. 
     
     
       6. A method as defined in claim 5, wherein said light absorbing material is a polymeric coating. 
     
     
       7. A method as defined in claim 6, wherein said polymeric coating is black. 
     
     
       8. A method as defined in claim 1, wherein said heating of said end includes: allowing a predetermined length of said end of said optical fiber to be exposed to a flame; and,   allowing said predetermined length of said end of said optical fiber to be exposed to said flame until a protective coating burns away from a portion of said glass fiber, and said glass fiber softens, and bends upward and forms a glass bead at the end of said optical fiber.   
     
     
       9. A low reflection termination device, comprising: a tubular glass housing having an interior cavity;   an optical fiber having an end, a portion of said end being formed by the application of heat into a glass bead, said glass bead having an index of refraction, said optical fiber extending into said glass housing with said glass bead positioned within said interior cavity;   a clear cured epoxy disposed within said cavity of said housing, said epoxy surrounding said glass bead; and   a light absorbing material coating said tubular glass housing.   
     
     
       10. A termination device as defined in claim 9, wherein said glass housing has an index of refraction approximately equal to the index of refraction of said glass bead. 
     
     
       11. A termination device as defined in claim 9, wherein said epoxy has an index of refraction approximately equal to the index of refraction of said glass bead. 
     
     
       12. A termination device as defined in claim 11, wherein said epoxy is ultraviolet (UV) light curing. 
     
     
       13. A termination device as defined in claim 9, wherein said glass bead is formed by exposing a portion of said end of said optical fiber to a heat source until a protective coating on said optical fiber burns away and said portion of said end softens to a glass bead. 
     
     
       14. A termination device as defined in claim 13, wherein glass bead is asymmetrical to the axis of said optical fiber. 
     
     
       15. A termination device as defined in claim 13, wherein said heat source is a gas flame. 
     
     
       16. A termination device as defined in claim 9, wherein said light absorbing material is polymeric material. 
     
     
       17. A termination device as defined in claim 16, wherein said polymeric material is black. 
     
     
       18. A method for terminating an end of an optical fiber, comprising the steps of: heating an end of an optical fiber to form a bead of glass thereon; and   encasing said end of said fiber in a housing containing a non-reflective material.   
     
     
       19. A method as defined in claim 18, wherein said material within said housing has an index of refraction approximately equal to the index of refraction of said bead of glass, and said housing is a glass tube that has an index of refraction approximately equal to the index of refraction of said bead of glass. 
     
     
       20. A method as defined in claim 19, wherein said light transmitting material is a solid. 
     
     
       21. A method as defined in claim 20, wherein said light transmitting material is a cured epoxy. 
     
     
       22. A method as defined in claim 19, wherein said light transmitting material has an index of refraction greater than the index of refraction of said bead of glass. 
     
     
       23. A low reflection termination device, comprising: a housing having a cavity therein;   an optical fiber having an end thereof formed into a bead of glass by the application of heat, said optical fiber extending into said housing with said bead of glass positioned within said cavity; and   a non-reflective material within said cavity of said housing surrounding said bead of glass.   
     
     
       24. A termination device as defined in claim 23, wherein said housing is a glass tube that has an index of refraction approximately equal to the index of refraction of said bead of glass and said material within said housing is light transmitting. 
     
     
       25. A termination device as defined in claim 24, wherein said light transmitting material is a solid. 
     
     
       26. A termination device as defined in claim 25, wherein said light transmitting material is a cured epoxy. 
     
     
       27. A termination device as defined in claim 26, wherein said epoxy is ultraviolet (UV) light curing. 
     
     
       28. A termination device as defined in claim 23, wherein said bead of glass is asymmetrical to the axis of said optical fiber. 
     
     
       29. A method of terminating an end of an optical fiber, comprising the steps of: exposing an end of a glass fiber of an optical fiber to a heat source for a predetermined period of time until said end softens and flows into a bead of glass at said end of said optical fiber;   surrounding said bead of glass and a portion of said optical fiber with a non-reflective material; and   encasing said non-reflective material in a rigid protective housing.   
     
     
       30. A method as defined in claim 29, wherein said non-reflective material is a light transmitting material. 
     
     
       31. A method as defined in claim 29, wherein said non-reflective material is a light absorbing material. 
     
     
       32. A method as defined in claim 29, wherein said glass fiber includes a protective coating and said heat source burns away said protective coating. 
     
     
       33. A method of forming an optical device, comprising the steps of: positioning an optical fiber having an inner glass fiber and a protective coating thereon in a fixture wherein a portion of said optical fiber is exposed;   exposing said portion of said optical fiber to a heat source; and   maintaining said portion of said optical fiber exposed to said heat until said protective coating is removed.   
     
     
       34. A method as defined in claim 33, wherein said portion of said optical fiber is exposed to said heat until said glass fiber is softened and forms a glass bead at the end thereof.